Search results for "thesis"
showing 10 items of 4193 documents
Inappropriate translation inhibition and P-body formation cause cold-sensitivity in tryptophan-auxotroph yeast mutants
2017
In response to different adverse conditions, most eukaryotic organisms, including Saccharomyces cerevisiae, downregulate protein synthesis through the phosphorylation of eIF2α (eukaryotic initiation factor 2α) by Gcn2, a highly conserved protein kinase. Gcn2 also controls the translation of Gcn4, a transcription factor involved in the induction of amino acid biosynthesis enzymes. Here, we have studied the functional role of Gcn2 and Gcn2-regulating proteins, in controlling translation during temperature downshifts of TRP1 and trp1 yeast cells. Our results suggest that neither cold-instigated amino acid limitation nor Gcn2 are involved in the translation suppression at low temperature. Howev…
Herbicide glufosinate inhibits yeast growth and extends longevity during wine fermentation.
2017
Glufosinate ammonium (GA) is a widely used herbicide that inhibits glutamine synthetase. This inhibition leads to internal amino acid starvation which, in turn, causes the activation of different nutrient sensing pathways. GA also inhibits the enzyme of the yeast Saccharomyces cerevisiae in such a way that, although it is not used as a fungicide, it may alter yeast performance in industrial processes like winemaking. We describe herein how GA indeed inhibits the yeast growth of a wine strain during the fermentation of grape juice. In turn, GA extends longevity in a variety of growth media. The biochemical analysis indicates that GA partially inhibits the nutrient sensing TORC1 pathway, whic…
Modulation of protein synthesis and degradation maintains proteostasis during yeast growth at different temperatures
2016
To understand how cells regulate each step in the flow of gene expression is one of the most fundamental goals in molecular biology. In this work, we have investigated several protein turnover-related steps in the context of gene expression regulation in response to changes in external temperature in model yeast Saccharomyces cerevisiae. We have found that the regulation of protein homeostasis is stricter than mRNA homeostasis. Although global translation and protein degradation rates are found to increase with temperature, the increase of the catalytic activity of ribosomes is higher than the global translation rate suggesting that yeast cells adapt the amount of translational machinery to…
A predominantly glial origin of axonal ribosomes after nerve injury
2017
Axonal mRNA transport and local protein synthesis are crucial for peripheral axon regeneration. To date, it remains unclear how ribosomes localize to axons. They may be co-transported with mRNAs or, as suggested by recent studies, transferred from Schwann cells (SC). Here, we generated transgenic "RiboTracker" mice expressing tdTomato-tagged ribosomal protein L4 in specific cell types when crossed with Cre lines. Two neuronal RiboTracker-Cre lines displayed extremely low levels of axonal L4-tdTomato-positive ribosomes. In contrast, two glial RiboTracker-Cre lines revealed tagged ribosomes in sciatic nerve (SN) axons with increasing amounts after injury. Furthermore, non-RiboTracker dorsal r…
Resistance against Echinostoma caproni (Trematoda) secondary infections in mice is not dependent on the ileal protein production
2016
Echinostoma caproni (Trematoda: Echinostomatidae) is an intestinal trematode, which has been widely employed to investigate the factors determining the rejection of intestinal helminths. Protein production patterns of intestinal epithelial cells are related to the infection-induced changes that determine the course of E. caproni infections. Herein, we compare the protein production profiles in the ileum of four experimental groups of mice: control; infected; dewormed and reinfected. Worm burdens were significantly lower in secondary infections, confirming the generation of partial resistance to homologous secondary infections in mice. However, quantitative comparison by 2D-DIGE showed that …
Non-Rapid Eye Movement Sleep Parasomnias and Migraine: A Role of Orexinergic Projections
2018
Introduction: Sleep and migraine share a common pathophysiological substrate, although the underlying mechanisms are unknown. The serotonergic and orexinergic systems are both involved in the regulation of sleep/wake cycle, and numerous studies show that both are involved in the migraine etiopathogenesis. These two systems are anatomically and functionally interconnected. Our hypothesis is that in migraine a dysfunction of orexinergic projections on the median raphe (MR) nuclei, interfering with serotonergic regulation, may cause Non-Rapid Eye Movement parasomnias, such as somnambulism. Hypothesis/theory: Acting on the serotonergic neurons of the raphe nuclei, the dysfunction of orexinergic…
Biological and chemical characterization of new isolated halophilic microorganisms from saltern ponds of Trapani, Sicily
2021
Abstract Halophilic microorganisms inhabiting hypersaline environments such as salt lakes, Dead Sea, or salt evaporation ponds, have acquired specific cell adaptation to grow within stressful conditions. In this study, we isolated heterotrophic and autotrophic microorganisms from several saltern ponds located at the Natural Reserve “Saline di Trapani e Paceco”, Sicily, Italy. The aim of the study was to investigate the biotechnological potential of new microbial strains from saltern ponds, by capturing their biological and chemical diversity. After the isolation and identification of the sampled strains, their growth capacity was determined under low and high salinity conditions. The metabo…
Diversity, virulence, and antimicrobial resistance of the KPC-producing Klebsiella pneumoniae ST307 clone
2017
ABSTRACT : The global spread of Klebsiella pneumoniae producing Klebsiella pneumoniae carbapenemase (KPC) has been mainly associated with the dissemination of high-risk clones. In the last decade, hospital outbreaks involving KPC-producing K. pneumoniae have been predominantly attributed to isolates belonging to clonal group (CG) 258. However, results of recent epidemiological analysis indicate that KPC-producing sequence type (ST) 307, is emerging in different parts of the world and is a candidate to become a prevalent high-risk clone in the near future. Here we show that the ST307 genome encodes genetic features that may provide an advantage in adaptation to the hospital environment and t…
Identification of microRNAS differentially regulated by water deficit in relation to mycorrhizal treatment in wheat.
2019
Arbuscular mycorrhizal fungi (AMF) are soil microrganisms that establish symbiosis with plants positively influencing their resistance to abiotic stresses. The aim of this work was to identify wheat miRNAs differentially regulated by water deficit conditions in presence or absence of AMF treatment. Small RNA libraries were constructed for both leaf and root tissues considering four conditions: control (irrigated) or water deficit in presence/absence of mycorrhizal (AMF) treatment. A total of 12 miRNAs were significantly regulated by water deficit in leaves: five in absence and seven in presence of AMF treatment. In roots, three miRNAs were water deficit-modulated in absence of mycorrhizal t…
Combining multiple hypothesis testing with machine learning increases the statistical power of genome-wide association studies
2016
Mieth, Bettina et al.